On Tuesday, the U.S. Federal Communications Commission (FCC) issued a public notice stating that more GPS interference tests are needed before LightSquared (Reston, Va., U.S.A.) can begin operations of its 4G-LTE nationwide wireless broadband network.

LightSquared, who originally submitted its final interference report on June 30th, later submitted proposed mitigation techniques after significant GPS interference was reported. These proposed mitigations included only using the lower 10 MHz portion of the spectrum. Originally, LightSquared planned on using both the upper and lower 10 MHz portions, but after significant “harmful interference” was reported, the company revised its plan.

“The results thus far from the testing using the lower 10MHz showed significant improvement compared to tests of the upper 10 MHz,” says the FCC in the notice. “Although, there continue to be interference concerns, e.g., with certain types of high precision GPS receivers, including devices used in national security and aviation applications. Additional tests are therefore necessary.”

On Monday, Martin Harriman, executive vice president at LightSquared, spoke at the Mobile Future Forward conference where he said that he expected GPS interference issued to be resolved within a month.

With the FCC’s new notice, it seems Harriman may have been wrong in his prediction.

“The new notice by the FCC represents another speed bump for LightSquared. Even though it means another delay, LightSquared has sufficient spectrum that they can have a viable business even though they will have to use a lot of it around the GPS band to avoid interference,” says Roger Entner, analyst at Recon Analytics. “The FCC is just being extra careful here, but ultimately I expect LightSquared to get the approval and provide service.”

Over the past two months, LightSquared has entered into multiple agreements with companies such as VoX Communications, Advanta Technologies, Simplexity MVNO Services, InterGlobe Communications and EarthComm Solutions, adding up to a total of 14 partner agreements thus far.